Risks Related to This Offering [Member] Risks Related to This Offering. Revolving Credit Facilities [Member] Revolving Credit Facilities. Convertible Senior Notes due 2019 [Member] Convertible Senior Notes due 2019. Convertible Senior Notes due 2022 [Member] Convertible Senior Notes due 2022. Twenty Thousand And Twenty Three Notes [Member] 2023 Notes Twenty Thousand And Twenty Three Notes. Twenty Thousand And Twenty Four Notes [Member] 2024 Notes Twenty Thousand And Twenty Three Notes. Twenty Thousand And Twenty Six Notes [Member] 2026 Notes Twenty Thousand And Twenty Six Notes. Common Shares [Member] Preferred Shares [Member]